What are the characteristics of Chinese cabbage planted by leafhoppers? How to reduce the harm?

There are more than 10000 kinds of leafhoppers in the world, and leafhoppers are often planted on Chinese cabbage. Both adults and larvae use stinging mouthparts to penetrate into plant tissues to absorb juice, and pale white spots will appear on the absorbed plant leaves, and in severe cases, spots will appear one after another. Make its branches and leaves wither until the whole leaves die. While sucking juice, leafhoppers also secrete a secret dew, which makes the tobacco leaves of plants sick, affects the photosynthesis of plants, and further leads to the death of plants, which is one of the main hazards of field crops.

Cicada is very harmful to Chinese cabbage, so what are the characteristics of Chinese cabbage when it is harmed by leaf worms? How to govern? Study with Brother Xueyan!

The growth habit of cicada Cicada belongs to the winged class of Insecta and the cephalobeak suborder of Hemiptera. Its eggs are milky oval and often attach to the stems or leaf sheaths of plants in summer. In winter, hide in hay or trees for the winter. In the larval stage, it will stay still and cling to the young leaves when feeding. Its adults are similar to cicadas, mostly yellow-green or yellow-white. It is good at jumping and has certain flying ability. When the sun is strong, it is more active and has light avoidance.

The damage characteristics of leafhoppers are mainly to the leaves of Chinese cabbage. If the leaves are found to be green, yellow and wilting, which affects the normal growth of Chinese cabbage, the leaves will fall off or even the whole plant will die, or when we check whether the vegetables encounter pests by hand, we will find green or yellow-green insects in the backlight of the leaves, especially when they are frightened, they will jump around and flee everywhere. At this time, it can be judged that the cabbage field has suffered the harm of leafhoppers.

Insect control 1, field cleaning: Prune branches or plants that have been damaged by leafhoppers, and it is best to burn them after pruning, so as to reduce the parasitic sites of insects and avoid further threats from pests, which can not only reduce the insect source of leafhoppers, but also avoid further losses of crops and large-scale death of Chinese cabbage.

2. Cultivation measures: Strengthen farmland management of Chinese cabbage. Clear weeds in the field in time in early spring or winter and bury them in a centralized way. Cicada has a strong reproductive ability, and can reproduce four or five generations a year. Especially in winter, adults lay eggs on the shady side of leaves or under the epidermis of branches, so we should clean up the dead weeds in the field in early spring or winter and remove them before the eggs hatch. In order to prevent large-scale insect pests after eggs hatch in the coming year, it will cause irreparable losses to Chinese cabbage.

Control measures 1, light trapping and killing: the adults are trapped and killed by using their characteristics of moving in sunny conditions and avoiding light. Tools on the market include black light and double-wave light. The light waves of black light and double-wave light are invisible to the naked eye, but some pests are very sensitive to this light wave, because many pests' visual nerves are particularly sensitive to ultraviolet rays with a wavelength of 330 nm to 400 nm, so the trapping effect is very good, and they can trap and kill pests such as leafhoppers. When black lights are placed in the fields at night, cicadas are lured and cannot escape after entering from the bottom. The hanging time is from the end of April to the end of 10, and the appropriate time to turn on the light is from 20: 00 to 2: 00 the next day. It will be good to last for a while.

2. Chemical control: each sprayer uses 4.5% beta-cypermethrin or other pyrethrins, 15 ml water or 10 ml emamectin benzoate or 5 ml chlorantraniliprole 20% suspension emulsion; Mix 10% imidacloprid 15g or 50% pymetrozine or 10% nitenpyram 10g.

But we should pay attention to: first, take medicine early; Second, use low-toxicity, high-efficiency and residue-free mixed drugs to create green and healthy Chinese cabbage. Chemical drugs must be targeted to treat a variety of pests, not just one pest, and it is best to control the harm before the seedlings of Chinese cabbage are fixed.

Preventive medication is mainly to protect seedlings. When Chinese cabbage emerges for 2-3 days, spray it for the first time. When spraying, remember that the pressure of the sprayer should be low and the nozzle should be close to the vegetable seedlings, so that the liquid medicine can penetrate into the soil through the seedlings to achieve the spraying effect and reduce the threat of nymphs. Secondly, the number of spraying should be determined according to the insect situation, generally about 5 days apart. If the insect situation in the field improves, the use of drugs should be reduced appropriately. When eating Chinese cabbage at seedling stage, you must stop taking medicine for more than 7 days to prevent pesticide residues from exceeding the standard and endangering human health. Finally, attention should be paid to the fragility of Chinese cabbage seedlings, and the spraying concentration must be controlled while selecting good chemicals to avoid white heart and burning of Chinese cabbage seedlings.

All of the above are personal planting experience sharing, which may not be comprehensive enough. I hope friends can discuss it together more.